1. Field of the Invention
The present invention relates to a multi-mode controller applied to a power converter and an operation method thereof, and particularly to a multi-mode controller and an operation method thereof that can control a power converter to switch between a quasi-resonant mode and a continuous-conduction mode through a soft-switching method.
2. Description of the Prior Art
When a load coupled to a secondary side of a power converter is changed, a controller applied to the power converter can control the power converter to switch between a quasi-resonant mode and a continuous-conduction mode, wherein the controller controls the power converter to switch between the quasi-resonant mode and the continuous-conduction mode according to a compensation voltage through a hard-switching method, and the compensation voltage corresponds to the load coupled to the secondary side of the power converter. However, because the controller utilizes the hard-switching method to make the power converter switch between the quasi-resonant mode and the continuous-conduction mode, the hard-switching method may make an operation frequency of the power converter be significantly changed, resulting in the power converter having greater switching loss and noise, and generating audio.